Separation conditions and evaluation of antioxidant properties of boldo ( Peumus boldus ) extracts

Abstract

Peumus boldus is an endemic plant from the Republic of Chile which possesses important biological activities attributing at its antioxidant activity. Boldine had been reported as the main bioactive component of boldo. However, recently it has been shown the contribution of polyphenolic compounds in its bioactivity. Boldine, total polyphenolic content and antioxidant activity from P. boldus were recovered under several extraction conditions to obtain further information on the correlation between boldine and phenolic content with the potential antioxidant of P. boldus . Antioxidant potential was evaluated by scavenging effects of DPPH (2,2 diphenyl-1-picrylhydrazyl) radicals. The boldine and phenolic content were determined by high performance liquid chromatography analysis (HPLC) analysis and Folin-Ciocalteu colorimetric assay respectively. Our results showed that boldine yield increased as extraction time was raised from 6 to 24 h, in contrast total polyphenolic content decreased at this time. The maximum boldine content observed was 1.2% in stem at 75°C after 24 h of extraction. While the maximum total polyphenolic content observed was 4% in leaves at 70°C after 6 h of extraction. The optimal extraction conditions for the maximal antioxidant activity were using leaves at 50°C and 6 h extraction under heat-reflux. Low relationship was observed between boldine content and antioxidant activity. The results indicated that the antioxidant activity of natural phenolic compounds from P. boldus is highly influenced by the extaction conditions employed.